The invention relates to a refillable muti-use container for highly viscous media that uses the first-in/first-out principle.
Highly viscous media, such as adhesives, fats, oils, pastes, etc. are usually loaded into drums by manufacturers and transported to the consumer. It is known for example from U.S. Pat. No. 4,790,456 to force a highly viscous medium upward through a riser out of a full drum by means of a descending compressor piston, but in this case, in accordance with the last-in/first-out principle, the medium that was last added to the drum is removed first, with the consequence that the medium that was loaded earlier and remains in the bottom area of the drum can become unusable and must be discarded. In addition, the expression of the medium from the drum can be impeded by air inclusions in the medium and may be rendered impossible.
For example, it is conventional in automobile manufacture to use adhesives prepared in known drums to glue together panels in the vehicle body. These adhesives are usually expressed from the drum in the manner described above and applied through a robot-controlled nozzle by means of a metering pump. During the operation of such automated devices, in addition to the problems mentioned above, it frequently happens that as the medium is being expressed from the drum, and especially when changing drums, ambient air comes in contact with the adhesive, triggering premature curing processes and resulting in clogging. As a result, the drum together with the remaining adhesive contained therein becomes unusable and must be discarded by the consumer at considerable expense.
In addition, the devices required for emptying the drum using a compression piston and a drive are very expensive and make the replacement of an empty drum by a new one undesirably cumbersome.
When an empty drum is being replaced by a full drum, medium often escapes with the result that the area becomes contaminated. Depending on the medium being used, this escape of the medium can also lead to the development of harmful vapors or the like, posing considerable problems. In addition, the drums used previously are intended for only a single use, increasing the cost of disposal.
A drum for highly viscous media that uses the first-in/first-out principle is known from U.S. Pat. No. 4,552,090, said drum having a removal channel formed in the bottom area and a follower plate that rests on the loaded medium.
The disadvantage of this known drum is that because it lacks suitable filling and ventilating and/or venting provisions, it is suitable for only a single use, and because it also has a costly follower plate, it does not make economic sense to use. When the known drum is used and then discarded, therefore, an unacceptably high cost is necessarily involved.